Two-level LED security light with motion sensor

ABSTRACT

A two-level LED security light includes a light emitting unit, a power supply unit, a loading and power control unit, a light sensing control unit, a motion sensing unit and a time setting unit. The lighting-emitting unit includes an LED load which may be turned on or turned off by the light sensing control unit and controlled by the loading and power control unit. When the motion sensing unit detects an intrusion, the LED load is switched to a high level illumination for a predetermined time length adjustable by the time setting unit. The LED load is configured with a plurality of LEDs accommodating to the power supply unit wherein a voltage V across each LED is confined in a range Vth&lt;V&lt;Vmax, with Vth being a minimum voltage to turn on the LED and Vmax a maximum voltage to avoid damaging the LED.

CROSS-REFERENCE TO RELATED APPLICATIONS

This is a continuation application of prior application Ser. No. 15/230,752 filed on Aug. 8, 2016, currently pending, which is a continuation application of prior application Ser. No. 14/478,150 filed on Sep. 5, 2014, issued as U.S. Pat. No. 9,445,474 on 13 Sep. 2016, which is a continuation application of prior application Ser. No. 13/222,090 filed on Aug. 31, 2011, issued as U.S. Pat. No. 8,866,392 on 21 Oct. 2014.

BACKGROUND 1. Technical Field

The present disclosure relates to a lighting apparatus, in particular, to a two-level security LED light with motion sensor

2. Description of Related Art

Lighting sources such as the fluorescent lamps, the incandescent lamps, the halogen lamps, and the light-emitting diodes (LED) are commonly found in lighting apparatuses for illumination purpose. Photo resistors are often utilized in outdoor lighting applications for automatic illuminations, known as the Photo-Control (PC) mode. Timers may be used in the PC mode for turning off the illumination or for switching to a lower level illumination of a lighting source after the lighting source having delivered a high level illumination for a predetermined duration, referred as the Power-Saving (PS) mode. Motion sensors are often used in the lighting apparatus for delivering full-power illumination thereof for a short duration when a human motion is detected, then switching back to the PS mode. Illumination operation controls such as auto-illumination in accordance to the background brightness detection, illumination using timer, illumination operation control using motion sensing results (e.g., dark or low luminous power to fully illuminated), and brightness control are often implemented by complex circuitries. In particular, the design and construction of LED drivers are still of a complex technology with high fabrication cost.

Therefore, how to develop a simple and effective design method on illumination controls such as enhancing contrast in illumination and color temperature for various types lighting sources, especially the controls for LEDs are the topics of the present disclosure.

SUMMARY

An exemplary embodiment of the present disclosure provides a two-level LED security light with motion sensor which may switch to high level illumination in the Power-Saving (PS) mode for a predetermined duration time when a human motion is detected thereby achieve warning purpose using method of electric current or lighting load adjustment. Furthermore, prior to the detection of an intrusion, the LED security light may be constantly in the low level illumination to save energy.

An exemplary embodiment of the present disclosure provides a two-level LED security light including a power supply unit, a light sensing control unit, a motion sensing unit, a loading and power control unit, and a light-emitting unit. The light-emitting unit further includes one or a plurality of series-connected LEDs; when the light sensing control unit detects that an ambient light is lower than a predetermined value, the loading and power control unit turns on the light-emitting unit to generate a high level or a low level illumination; when the light sensing control unit detects that the ambient light is higher than the predetermined value, the loading and power control unit turns off the light-emitting unit; when the motion sensing unit detects a human motion in the PS mode, the loading and power control unit increases the electric current that flows through the light-emitting unit so as to generate the high level illumination for a predetermined duration.

Another exemplary embodiment of the present disclosure provides a two-level LED security light including a power supply unit, a light sensing control unit, a motion sensing unit, a loading and power control unit, a light-emitting unit. The light-emitting unit includes a plurality of series-connected LEDs. When the light sensing control unit detects that an ambient light is lower than a predetermined value, the loading and power control unit turns on a portion or all the LEDs of the light-emitting unit to generate a low level or a high level illumination; when the light sensing control unit detects that the ambient light is higher than the predetermined value, the loading and power control unit turns off all the LEDs in the light-emitting unit; when the motion sensing unit detects a human motion in the PS mode, the loading and power control unit turns on a plurality of LEDs in the light-emitting unit and generates the high level illumination for a predetermine duration. An electric current control circuit is integrated in the exemplary embodiment for providing constant electric current to drive the LEDS in the light-emitting unit.

One exemplary embodiment of the present disclosure provides a two-level LED security light including a power supply unit, a light sensing control unit, a motion sensing unit, a loading and power control unit, and a light-emitting unit. The light-emitting unit includes one or a plurality of parallel-connected alternating current (AC) LEDs. A phase controller is coupled between the described one or a plurality parallel-connected ACLEDs and AC power source. The loading and power control unit may through the phase controller control the average power of the light-emitting unit; when the light sensing control unit detects that an ambient light is lower than a predetermined value, the loading and power control unit turns on the light-emitting unit to generate a high level or a lower level illumination; when the light sensing control unit detects that the ambient light is higher than the predetermined value, the loading and power control unit turns off the light-emitting unit; when the motion sensing unit detects a human motion in the PS mode, the loading and power control unit increases the average power of the light-emitting unit thereby generates the high level illumination for a predetermine duration.

According to an exemplary embodiment of the present disclosure, a two-level LED security light includes a power supply unit, a light sensing control unit, a motion sensing unit, a loading and power control unit, and a light-emitting unit. The light-emitting unit includes X high wattage ACLEDs and Y low wattage ACLEDs connected in parallel. When the light sensing control unit detects that an ambient light is lower than a predetermined value, the loading and power control unit turns on the plurality of low wattage ACLEDs to generate a low level illumination; when the light sensing control unit detects that the ambient light is higher than a predetermined value, the loading and power control unit turns off the light-emitting unit; when the motion sensor detects an intrusion, the loading and power control unit turns on both the high wattage ACLEDs and the low wattage ACLEDs at same time thereby generates a high level illumination for a predetermine duration, wherein X and Y are of positive integers.

According to an exemplary embodiment of the present disclosure, a two-level LED security light with motion sensor includes a power supply unit, a light sensing control unit, a motion sensing unit, a loading and power control unit, and a light-emitting unit. The light-emitting unit includes a rectifier circuit connected between one or a plurality of parallel-connected AC lighting sources and AC power source. The loading and power control unit may through the rectifier circuit adjust the average power of the light-emitting unit. When the light sensing control unit detects that an ambient light is lower than a predetermined value, the loading and power control unit turns on the light-emitting unit to generate a low level illumination; when the light sensing control unit detects that the ambient light is higher than the predetermined value, the loading and power control unit turns off the light-emitting unit; when the motion sensing unit detects an intrusion, the loading and power control unit increases the average power of the light-emitting unit thereby generates a high level illumination for a predetermine duration. The rectifier circuit includes a switch parallel-connected with a diode, wherein the switch is controlled by the loading and power control unit.

To sum up, a two-level LED security light with motion sensor provided by an exemplary embodiment in the preset disclosure, may execute Photo-Control (PC) and Power-Saving (PS) modes. When operates in the PC mode, the lighting apparatus may auto-illuminate at night and auto turn off at dawn. The PC mode may generate a high level illumination for a predetermined duration then automatically switch to the PS mode by a control unit to generate a low level illumination. When the motion sensor detects a human motion, the disclosed LED security light may immediately switch to the high level illumination for a short predetermined duration thereby achieve illumination or warning effect. After the short predetermined duration, the LED security light may automatically return to the low level illumination for saving energy. The PC mode may alternatively generate the low level illumination to begin with and when the motion sensor is detected the disclosed LED security may immediately switch to a high level illumination for a short predetermined duration to provide security protection and then automatically return to the low level illumination.

In order to further understand the techniques, means and effects of the present disclosure, the following detailed descriptions and appended drawings are hereby referred, such that, through which, the purposes, features and aspects of the present disclosure can be thoroughly and concretely appreciated; however, the appended drawings are merely provided for reference and illustration, without any intention to be used for limiting the present disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings are included to provide a further understanding of the present disclosure, and are incorporated in and constitute a part of this specification. The drawings illustrate exemplary embodiments of the present disclosure and, together with the description, serve to explain the principles of the present disclosure.

FIG. 1 schematically illustrates a block diagram of a two-level LED security light in accordance with an exemplary embodiment of the present disclosure.

FIG. 2A illustrates a schematic diagram of a two-level LED security light in accordance to the first exemplary embodiment of the present disclosure.

FIG. 2B graphically illustrates a timing waveform of a pulse width modulation (PWM) signal in accordance to the first exemplary embodiment of the present disclosure.

FIG. 3A illustrates a schematic diagram of a two-level LED security light in accordance to the second exemplary embodiment of the present disclosure.

FIG. 3B illustrates a schematic diagram of a two-level LED security light in accordance to the second exemplary embodiment of the present disclosure.

FIG. 4A illustrates a schematic diagram of a two-level LED security light in accordance to the third exemplary embodiment of the present disclosure.

FIG. 4B illustrates a timing waveform of two-level LED security light in accordance to the third exemplary embodiment of the present disclosure.

FIG. 5 illustrates a schematic diagram of a two-level LED security light in accordance to the third exemplary embodiment of the present disclosure.

FIG. 6 illustrates a schematic diagram of a two-level LED security light in accordance to the fourth exemplary embodiment of the present disclosure.

FIG. 7 illustrates a schematic diagram of a two-level LED security light in accordance to the fifth exemplary embodiment of the present disclosure.

DESCRIPTION OF THE EXEMPLARY EMBODIMENTS

Reference is made in detail to the exemplary embodiments of the present disclosure, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers are used in the drawings and the description to refer to the same or alike parts.

First Exemplary Embodiment

Refer to FIG. 1, which schematically illustrates a block diagram of a two-level LED security light in accordance to the first exemplary embodiment of the present disclosure. A two-level LED security light (herein as the lighting apparatus) 100 includes a power supply unit 110, a light sensing control unit 120, a motion sensing unit 130, a loading and power control unit 140, and a light-emitting unit 150. The power supply unit 110 is used for supplying power required to operate the system, wherein the associated structure includes the known AC/DC voltage converter. The light sensing control unit 120 may be a photoresistor, which may be coupled to the loading and power control unit 140 for determining daytime or nighttime in accordance to the ambient light. The motion sensing unit 130 may be a passive infrared sensor (PIR), which is coupled to the loading and power control unit 140 and is used to detect intrusions. When a person is entering a predetermined detection zone of the motion sensing unit 130, a sensing signal thereof may be transmitted to the loading and power control unit 140.

The loading and power control unit 140 which is coupled to the light-emitting unit 150 may be implemented by a microcontroller electrically coupled with a switching circuitry electrically connected between the light emitting unit 150 and the power supply unit 110. The switching circuitry may comprise a plurality of semiconductor switching components. The loading and power control unit 140 may control the illumination levels of the light-emitting unit 150 in accordance to the sensing signal outputted by the light sensing control unit 120 and the motion sensing unit 130. The light-emitting unit 150 may include a plurality of LEDs. The loading and power control unit 140 may control the light-emitting unit 150 to generate at least two levels of illumination variations.

When the light sensing control unit 120 detects that an ambient light is lower than a predetermined value (i.e., nighttime), the loading and power control unit 140 executes the Photo-Control (PC) mode by turning on the light-emitting unit 150 to generate a high level illumination for a predetermined duration then return to a low level illumination for Power-Saving (PS) mode or it may alternatively generate the low level illumination to perform the power saving mode. When the light sensing control unit 120 detects that the ambient light is higher than a predetermined value (i.e., dawn), the loading and power control unit 140 turns off the light-emitting unit 150. In the PS mode, when the motion sensing unit 130 detects a human motion, the loading and power control unit 140 may increase the electric current which flows through the light-emitting unit 150, to generate another high level illumination for a short predetermined duration. After the short predetermined duration, the loading and power control unit 140 may automatically lower the electric current that flow through the light-emitting unit 150 thus have the light-emitting unit 150 return to low level illumination for saving energy.

Refer to 2A, which illustrates a schematic diagram of a two-level LED security light in accordance to the first exemplary embodiment of the present disclosure. The light sensing control unit 120 may be implemented by a light sensor 220; the motion sensing unit 130 may be implemented by a motion sensor 230; the loading and power control unit 140 may be implemented by a microcontroller 240 electrically coupled to a switching circuitry Q1. The light-emitting unit 250 includes three series-connected LEDs L1˜L3. The LEDs L1˜L3 is connected between a DC source and a transistor Q1, wherein the DC source may be provided by the power supply unit 110. The transistor Q1 may be an N-channel metal-oxide-semiconductor field-effect-transistor (NMOS). The transistor Q1 is connected between the three series-connected LEDs L1˜L3 and a ground GND. The loading and power control unit 140 implemented by the microcontroller 240 may output a control signal like a pulse width modulation (PWM) signal to control an average electric current delivered to the light emitting unit 250. It is worth to note that the electric components depicted in FIG. 2A only serves as an illustration for the exemplary embodiment of the present disclose and hence the present disclosure is not limited thereto.

Refer to FIG. 2B concurrently, which graphically illustrates a timing waveform of a pulse width modulation (PWM) signal in accordance to the first exemplary embodiment of the present disclosure. In the PC mode, the PWM signal may be used to configure the transistor Q1 to have the conduction period T_(on) being longer than the cut-off period T_(off). On the other hand in the PS mode, the PWM signal may configure the transistor Q1 to have the conduction period T_(on) being shorter than the cut-off period T_(off). In comparison of the illumination levels between the PC and PS modes, as the conduction period T_(on) of transistor Q1 being longer under the PC mode, therefore have higher average electric current driving the light-emitting unit 250 thereby generate high illumination, which may be classified as the high level illumination; whereas as the conduction period T_(on) of transistor Q1 is shorter in the PS mode, therefore have lower average electric current driving the light-emitting unit 250 thereby generate low illumination, which may be classified as the low level illumination.

The microcontroller 240 turns off the light-emitting unit 250 during the day and activates the PC mode at night by turning on the light-emitting unit 250 to generate the high level illumination for a short predetermined duration then return to the low level illumination thereby entering the PS mode. When the motion sensor 230 detects a human motion in the PS mode, the light-emitting unit 250 may switch to the high level illumination for illumination or warning application. The light-emitting unit 250 may return to the low level illumination after maintaining at the high level illumination for a short predetermined duration to save energy.

In addition, the microcontroller 240 is coupled to a time setting unit 260, wherein the time setting unit 260 may allow a user to configure the predetermined duration associated with the high level illumination in the PC mode, however the present disclosure is not limited thereto. The time setting unit 260 may also be used for setting a predetermined time duration associated with the low level illumination as well as a predetermined time duration associated with a motion activated high level illumination. The time setting unit 260 is typically configured with an analogue circuitry comprising a resister and a capacitor for setting a time length. However, if precision of time length is crucial or much preferred, a digital circuitry may be employed, wherein a voltage divider with a variable resister coupled to the microcontroller designed with a time setting subroutine or a push button device coupled with a grounding pin of the microcontroller designed with the time setting subroutine for more precisely setting a time length for performing an illumination mode.

Second Exemplary Embodiment

Refer again to FIG. 1, wherein the illumination variations of the light-emitting unit 150 may be implemented through the number of light-source loads being turned on to generate more than two levels of illumination. The lighting apparatus 100 in the instant exemplary embodiment may be through turning on a portion of LEDs or all the LEDs to generate a low and a high level of illuminations.

Refer to FIG. 3A concurrently, which illustrates a schematic diagram of a two-level LED security light 100 in accordance to the second exemplary embodiment of the present disclosure. The main difference between FIG. 3A and FIG. 2A is in the light-emitting unit 350, having three series-connected LEDs L1˜L3 and NMOS transistors Q1 and Q2. The LEDs L1˜L3 are series connected to the transistor Q1 at same time connected between the DC source and a constant electric current control circuit 310. Moreover, transistor Q2 is parallel connected to the two ends associated with LEDs L2 and L3. The gates of the transistors Q1 and Q2 are connected respectively to a pin PC and a pin PS of the microcontroller 240. The constant electric current control circuit 310 in the instant exemplary embodiment maintains the electric current in the activated LED at a constant value, namely, the LEDs L1˜L3 are operated in constant-current mode.

Refer to FIG. 3A, the pin PC of the microcontroller 240 controls the switching operations of the transistor Q1; when the voltage level of pin PC being either a high voltage or a low voltage, the transistor Q1 may conduct or cut-off, respectively, to turn the LEDs L1˜L3 on or off. The pin PS of the microcontroller 240 controls the switch operations of the transistor Q2, to form two current paths 351 and 352 on the light-emitting unit 350. When the voltage at the pin PS of the microcontroller 240 is high, the transistor Q2 conducts, thereby forming the current path 351 passing through the LED L1 and the transistor Q2; when the voltage at the pin PS being low, the transistor Q2 cuts-off, thereby forming the current path 352 passing through all the LEDs L1˜L3. The microcontroller 240 may then control the switching operation of the transistor Q2 to turn on the desired number of LEDs so as to generate a high or a low level illumination.

When light sensor 220 determines that an ambient light is higher than a predetermined value, the microcontroller 240 through the pin PC outputs a low voltage, which causes the transistor Q1 to cut-off and turns off all the LEDs L1˜L3 in the light-emitting unit 350. Conversely, when the light sensor 220 detects that the ambient light is lower than the predetermined value, the microcontroller 240 activates the PC mode, i.e., outputting a high voltage from pin PC and a low voltage from pin PS, to activate the transistor Q1 while cut-off the transistor Q2, thereby forming the current path 352, to turn on the three LEDs L1˜L3 in the light-emitting unit 350 so as to generate the high level illumination for a predetermined duration. After the predetermined duration, the microcontroller 240 may switch to the PS mode by having the pin PC continue outputting a high voltage and the pin PS outputting a high voltage, to have the transistor Q2 conducts, thereby forming the current path 351. Consequently, only the LED L1 is turned on and the low level illumination is generated.

When the motion sensor detects a human motion in the PS mode, the pin PS of the microcontroller 240 temporarily switches from the high voltage to a low voltage, to have the transistor Q2 temporarily cuts-off thus forming the current path 352 to activate all the LEDs in the light-emitting unit 350, thereby temporarily generates the high level illumination. The light-emitting unit 350 is driven by a constant electric current, therefore the illumination level generated thereof is directly proportional to the number of LEDs activated. FIG. 3B illustrates another implementation for FIG. 3A, wherein the relays J1 and J2 are used in place of NMOS transistors to serve as switches. The microcontroller 240 may control the relays J2 and J1 through regulating the switching operations of the NPN bipolar junction transistors Q4 and Q5. Moreover, resistors R16 and R17 are current-limiting resistors.

In the PC mode, the relay J1 being pull-in while the relay J2 bounce off to have constant electric current driving all the LEDs L1˜L3 to generate the high level illumination; in PS mode, the relays J1 and J2 both pull-in to have constant electric current only driving the LED L1 thus the low level illumination may be thereby generated. Furthermore, when the motion sensor 230 detects a human motion, the pin PS of the microcontroller 240 may temporarily switch from high voltage to low voltage, forcing the relay J2 to temporarily bounce off and the relay J1 pull-in so as to temporarily generate the high level illumination.

The LED L1 may adopt a LED having color temperature of 2700K while the LEDs L2 and L3 may adopt LEDs having color temperature of 5000K in order to increase the contrast between the high level and the low level illuminations. The number of LEDs included in the light-emitting unit 350 may be more than three, for example five or six LEDs. The transistor Q2 may be relatively parallel to the two ends associated with a plurality of LEDs to adjust the illumination difference between the high and the low illumination levels. Additionally, the light-emitting unit 350 may be connected to a plurality of transistors Q2, which are respectively coupled to the two ends associated with each LED to provide more lighting variation selections. The microcontroller 240 may decide the number of LEDs to turn on in accordance to design needs at different conditions. Based on the explanation of the aforementioned exemplary embodiment, those skills in the art should be able to deduce other implementation and further descriptions are therefore omitted.

Third Exemplary Embodiment

Refer back to FIG. 1, wherein the light-emitting unit 150 may include one or more parallel-connected alternating current (AC) LEDs. A phase controller is coupled between the described one or more parallel-connected ACLEDs and AC power source. The loading and power controller 140 in the instant exemplary embodiment may through the phase controller adjust the average power of the light-emitting unit 150 so as to generate variations in the low level and the high level illuminations.

Refer to FIG. 4A, which illustrates a schematic diagram of a two-level LED security light 100 in accordance to the third exemplary embodiment of the present disclosure. The main difference between FIG. 4A and FIG. 3 is in that the light-source load is an ACLED, which is coupled to the AC power source, and further the light-emitting unit 450 is connected to a phase controller 451. The phase controller 451 includes a bi-directional switching device 452, here, a triac, a zero-crossing detection circuit 453, and a resistor R. The microcontroller 240 turns off the light-emitting unit 450 when the light sensor 220 detects that the ambient light is higher than a predetermined value. Conversely, when the light sensor 220 detects that the ambient light is lower than the predetermined value, the microcontroller 240 activates the PC mode by turning on the light-emitting unit 450. In the PC mode, the microcontroller 240 may select a control pin for outputting a pulse signal which through a resistor R triggers the triac 452 to have a large conduction angle. The large conduction angle configures the light-emitting unit 450 to generate a high level illumination for a predetermined duration. Then the microcontroller 240 outputs the pulse signal for PS mode through the same control pin to trigger the triac 452 to have a small conduction angle for switching the light-emitting unit 450 from the high level illumination to the low level illumination of the PS mode. Moreover, when the motion sensor 230 (also called motion sensing unit) detects a human motion in the PS mode, the microcontroller 240 temporarily outputs the PC-mode pulse signal through the same control pin to have the light-emitting unit 450 generated the high level illumination for a short predetermined duration. After the short predetermined duration, the light-emitting unit 450 returns to the low level illumination.

In the illumination control of the ACLED, the microcontroller 240 may utilize the detected zero-crossing time (e.g., the zero-crossing time of an AC voltage waveform) outputted from the zero-crossing detection circuit 453 to send an AC synchronized pulse signal thereof which may trigger the triac 452 of the phase controller 451 thereby to change the average power input to the light-emitting unit 450. As the ACLED has a cut-in voltage V_(t) for start conducting, thus if the pulse signal inaccurately in time triggers the conduction of the triac 452, then the instantaneous value of AC voltage may be lower than the cut-in voltage V_(t) of ACLED at the trigger pulse. Consequently, the ACLED may result in the phenomenon of either flashing or not turning on. Therefore, the pulse signal generated by the microcontroller 240 must fall in a proper time gap behind the zero-crossing point associated with the AC sinusoidal voltage waveform.

Supposing an AC power source having a voltage amplitude V_(m) and frequency f, then the zero-crossing time gap t_(D) of the trigger pulse outputted by the microcontroller 240 should be limited according to t_(o)<t_(D)<½_(f)−t_(o) for a light-source load with a cut-in voltage V_(t), wherein t_(o)=(½πf)sin⁻¹(V_(t)/V_(m)). The described criterion is applicable to all types of ACLEDs to assure that the triac 452 can be stably triggered in both positive and negative half cycle of the AC power source. Take ACLED with V_(t)(rms)=80V as an example, and supposing the V_(m)(rms)=110V and f=60 Hz, then t_(o)=2.2 ms and (½f)=8.3 ms may be obtained. Consequently, the proper zero-crossing time gap t_(D) associated with the phase modulation pulse outputted by the microcontroller 240 which lagged the AC sinusoidal voltage waveform should be designed in the range of 2.2 ms<t_(D)<6.1 ms.

Refer to FIG. 4B, which illustrates a timing waveform of the two-level LED security light in accordance to the third exemplary embodiment of the present disclosure. Waveforms (a)˜(d) of FIG. 4B respectively represent the AC power source, the output of the zero-crossing detection circuit 453, the zero-crossing delay pulse at the control pin of the microcontroller 240, and the voltage waveform across the two ends of the ACLED in the light-emitting unit 450. The zero-crossing detection circuit 453 converts the AC voltage sinusoidal waveform associated with the AC power source to a symmetric square waveform having a low and a high voltage levels as shown in FIG. 4B(b). At the zero-crossing point of the AC voltage sinusoidal wave, the symmetric square waveform may transit either from the low voltage level to the high voltage level or from the high voltage level to the low voltage level. Or equivalently, the edge of the symmetric square waveform in the time domain corresponds to the zero-crossing point of the AC voltage sinusoidal waveform. As shown in FIG. 4B(c), the microcontroller 240 outputs a zero-crossing delay pulse in correspondence to the zero-crossing point of the AC sinusoidal waveform in accordance to the output waveform of the zero-crossing detection circuit 453. The zero-crossing delay pulse is relative to an edge of symmetric square waveform behind a time gap t_(D) in the time domain. The t_(D) should fall in a valid range, as described previously, to assure that the triac 452 can be stably triggered thereby to turn on the ACLED. FIG. 4B(d) illustrates a voltage waveform applied across the two ends associated with the ACLED. The illumination level of the light-emitting unit 450 is related to the conduction period t_(on) of the ACLED, or equivalently, the length t_(on) is directly proportional to the average power inputted to the ACLED. The difference between the PC mode and the PS mode being that in the PC mode, the ACLED has longer conduction period, thereby generates the high level illumination; whereas in the PS mode, the ACLED conduction period is shorter, hence generates the low level illumination.

Refer to FIG. 5, which illustrates a schematic diagram of a two-level LED security light 100 in accordance to the third exemplary embodiment of the present disclosure. The light-emitting unit 550 of the lighting apparatus 100 includes an ACLED1, an ACLED2. The phase controller 551 includes triacs 552 and 553, the zero-crossing detection circuit 554 as well as resistors R1 and R2. The light-emitting unit 550 of FIG. 5 is different from the light-emitting unit 450 of FIG. 4 in that the light-emitting unit 550 has more than one ACLED and more than one bi-directional switching device. Furthermore, the color temperatures of the ACLED1 and the ACLED2 may be selected to be different.

In the exemplary embodiment of FIG. 5, the ACLED1 has a high color temperature, and the ACLED2 has a low color temperature. In the PC mode, the microcontroller 240 uses the phase controller 551 to trigger both ACLED1 and ACLED2 to conduct for a long period, thereby to generate the high level illumination as well as illumination of mix color temperature. In the PS mode, the microcontroller 240 uses the phase controller 551 to trigger only the ACLED2 to conduct for a short period, thereby generates the low level illumination as well as illumination of low color temperature. Moreover, in the PS mode, when the motion sensor 230 detects a human motion, the microcontroller 240 may through the phase controller 551 trigger the ACLED1 and ACLED2 to conduct for a long period. Thereby, it may render the light-emitting unit 450 to generate the high level illumination of high color temperature and to produce high contrast in illumination and hue, for a short predetermined duration to warn the intruder. Consequently, the lighting apparatus may generate the high level or the low level illumination of different hue. The rest of operation theories associated with the light-emitting unit 550 are essentially the same as the light-emitting unit 450 and further descriptions are therefore omitted.

Fourth Exemplary Embodiment

Refer to FIG. 6, which illustrates a schematic diagram of a two-level LED security light 100 in accordance to the fourth exemplary embodiment of the present disclosure. The light-emitting unit 150 of FIG. 1 may be implemented by the light-emitting unit 650, wherein the light-emitting unit 650 includes three ACLED1˜3 having identical luminous power electrically connected to switches 651 and 652. In which, switches 651 and 652 may be relays. The parallel-connected ACLED1 and ACLED2 are series-connected to the switch 652 to produce double luminous power, and of which the ACLED3 is parallel connected to, to generate triple luminous power, and of which an AC power source is further coupled to through the switch 651. Moreover, the microcontroller 240 implements the loading and power control unit 140 of FIG. 1. The pin PC and pin PS are respectively connected to switches 651 and 652 for outputting voltage signals to control the operations of switches 651 and 652 (i.e., open or close).

In the PC mode, the pin PC and pin PS of the microcontroller 240 control the switches 651 and 652 to be closed at same time. Consequently, the ACLED1˜3 are coupled to the AC power source and the light-emitting unit 650 may generate a high level illumination of triple luminous power. After a short predetermined duration, the microcontroller 240 returns to PS mode. In which the switch 651 is closed while the pin PS controls the switch 652 to be opened, consequently, only the ACLED3 is connected to AC power source, and the light-emitting unit 650 may thus generate the low level illumination of one luminous power. In the PS mode, when the motion sensor 230 detects a human motion, the microcontroller 240 temporarily closes the switch 652 to generate high level illumination with triple luminous power for a predetermined duration. After the predetermined duration, the switch 652 returns to open status thereby to generate the low level illumination of one luminous power. The lighting apparatus of FIG. 6 may therefore through controlling switches 651 and 652 generate two level illuminations with illumination contrast of at least 3 to 1.

The ACLED1 and ACLED2 of FIG. 6 may be high power lighting sources having color temperature of 5000K. The ACLED3 may be a low power lighting source having color temperature of 2700K. Consequently, the ACLED may generate two levels of illuminations with high illumination and hue contrast without using a zero-crossing detection circuit.

Fifth Exemplary Embodiment

Refer to FIG. 7, which illustrates a schematic diagram of a two-level LED security light in accordance to the fifth exemplary embodiment of the present disclosure. The light-emitting unit 750 of FIG. 7 is different from the light-emitting unit 640 of FIG. 6 in that the ACLED3 is series-connected to a circuit with a rectified diode D and a switch 753 parallel-connected together, and of which is further coupled through a switch 751 to AC power source. When the switch 753 closes, the AC electric current that passes through the ACLED3 may be a full sinusoidal waveform. When the switch 753 opens, the rectified diode rectifies the AC power, thus only one half cycle of the AC electric current may pass through the ACLED, consequently the luminous power of ACLED3 is cut to be half.

The pin PS of the microcontroller 240 synchronously controls the operations of switches 752 and 753. If the three ACLED1˜3 have identical luminous power, then in the PC mode, the pin PC and pin PS of the microcontroller 240 synchronously close the switches 751˜753 to render ACLED1˜3 illuminating, thus the light-emitting unit 750 generates a high level illumination which is three-times higher than the luminous power of a single ACLED. When in the PS mode, the microcontroller 240 closes the switch 751 while opens switches 752 and 753. At this moment, only the ACLED3 illuminates and as the AC power source is rectified by the rectified diode D, thus the luminous power of ACLED3 is half of the AC power source prior to the rectification. The luminous power ratio between the high level and the low level illuminations is therefore 6 to 1. Consequently, strong illumination contrast may be generated to effectively warn the intruder.

It should be noted that the light-emitting unit in the fifth exemplary embodiment is not limited to utilizing ACLEDs. In other words, the light-emitting unit may include any AC lighting sources such as ACLEDs, incandescent lamps, or fluorescent lamps.

In respect to the LED load of the light emitting unit 150, the cut-in voltage V_(t) of ACLEDs or a plurality of LEDs is attributable to unique electrical characteristics of a light emitting diode, which are completely different from the conventional incandescent light bulb. The light emitting diode is made with a semiconductor material characterized with three unique electrical features, the first feature is one way conduction, the second feature is a minimum threshold voltage V_(th) to trigger each light emitting diode to start emitting light and the third feature is a maximum working voltage V_(max) allowed to impose on each light emitting diode to avoid a thermal damage or burning out the semiconductor construction of the light emitting diode. The described cut-in voltage V_(t) refers to a total threshold voltage of the light emitting unit 150 while the minimum threshold voltage V_(th) and the maximum working voltage V_(max) are related to individual light emitting diode. For each light emitting diode of the light emitting unit 150, regardless the light-source load being configured with an AC LED module or a DC LED module, the working voltage of each light emitting diode is confined to operate in a domain established by the minimum threshold V_(th) and the maximum working voltage V_(max). It is required that the configuration of the light emitting unit and the power source is designed with a configuration of in series and/or in parallel connections such that the electric current passing through each LED of the light emitting unit remains at an adequate level and thus a voltage V across each LED of the LED lamp complies with an operating constraint of V_(th)<V<V_(max) featuring electrical characteristics of the LED, wherein V_(th) is a minimum threshold voltage required to trigger each LED to start emitting light and V_(max) is a maximum operating voltage across each LED to avoid a thermal damage or burning out a semiconductor structure of the LED construction. The voltage operating domain characterized by V_(th)<V<V_(max) is in practice restricted in a range between 2.5 volts and 20 volts. Such narrow operating range therefore posts an engineering challenge for a circuit designer to successfully design a reliable circuitry configured with an adequate combination of in series connection and in parallel connection for operating a higher power LED security light.

A lighting apparatus may be implemented by integrating a plurality of LEDs with a microcontroller and various types of sensor components in the controlling circuit in accordance to the above described five exemplary embodiments. This lighting apparatus may automatically generate high level illumination when the ambient light detected is insufficient and time-switch to the low level illumination. In addition, when a person is entering the predetermined detection zone, the lighting apparatus may switch from the low level illumination to the high level illumination, to provide the person with sufficient illumination or to generate strong illumination and hue contrast for monitoring the intruder.

The above-mentioned descriptions represent merely the exemplary embodiment of the present disclosure, without any intention to limit the scope of the present disclosure thereto. Various equivalent changes, alternations or modifications based on the claims of present disclosure are all consequently viewed as being embraced by the scope of the present disclosure. 

What is claimed is:
 1. An LED security light, comprising: a light-emitting unit, including an LED load configured with a plurality of LEDs; a loading and power control unit; a light sensing control unit; a motion sensing unit; and a power supply unit; wherein the light-emitting unit is angle adjustable to provide illumination projection for security protection, wherein the loading and power control unit comprises a controller and a switching circuitry, wherein the controller is electrically coupled with the switching circuitry, wherein the switching circuitry is electrically connected between a power source and the LED load of the light-emitting unit, wherein the LED load is turned on or turned off by the light sensing control unit and controlled by the loading and power control unit, wherein the switching circuitry comprises at least a semiconductor switching device for controlling transmission of different average electric powers delivered to the LED load, wherein the controller outputs a control signal to control the switching circuitry for delivering different average electric powers from the power source to drive the light-emitting unit for generating different illuminations, wherein the controller controls the switching circuitry to deliver different average electric powers to the LED load such that the light-emitting unit respectively generates at least a low level illumination and at least a high level illumination to perform different illumination modes according to signals received from the light sensing control unit and the motion sensing unit; wherein the power supply unit includes an AC/DC power converter to convert AC power into DC powers required for operating the LED security light, wherein the power source is a DC power source configured in the power supply unit, wherein the semiconductor switching device is an unidirectional semiconductor switching device, wherein the control signal is a pulse width modulation signal to control the switching circuitry for delivering different average electric currents from the power source to drive the light-emitting unit for generating different illuminations; wherein a configuration of the LED load and the power source is designed to be an adequate combination of in parallel and in series connections such that the average electric current passing through each LED of the LED load remains at an adequate level and a voltage V across each LED of the LED load complies with an operating constraint of V_(th)<V<V_(max) featuring electrical characteristics of the LED, wherein V_(th) is a minimum threshold voltage required to trigger the LED to start emitting light and V_(max) is a maximum operating voltage across the LED to avoid a thermal damage or burning out of LED construction.
 2. The LED security light according to claim 1, wherein the value of V_(th) is equal to or greater than 2.5 volts, wherein the value of V_(max) is in a range between 3.5 volts and 20 volts depending on a packaging specification of the LED.
 3. The LED security light according to claim 2, wherein the value of the voltage V across each LED is confined to be in an operating range from 2.5 volts to 20 volts.
 4. The LED security light according to claim 1, wherein the controller is an integrated circuit device programmable for generating the control signal.
 5. The LED security light according claim 1, wherein the controller is an application specific integrated circuit customized for generating the control signal.
 6. An LED security light, comprising: a light-emitting unit, including an LED load configured with a plurality of LEDs; a loading and power control unit; a light sensing control unit; a motion sensing unit; and a power supply unit; wherein the light-emitting unit is angle adjustable to provide illumination projection for security protection, wherein the loading and power control unit comprises a controller and a switching circuitry, wherein the controller is electrically coupled with the switching circuitry, wherein the switching circuitry is electrically connected between a power source and the LED load of the light-emitting unit, wherein the LED load is turned on or turned off by the light sensing control unit and controlled by the loading and power control unit, wherein the switching circuitry comprises at least a semiconductor switching device for controlling transmission of different average electric powers delivered to the LED load, wherein the controller outputs a control signal to control the switching circuitry for delivering different average electric powers from the power source to drive the light-emitting unit for generating different illuminations, wherein the controller controls the switching circuitry to deliver different average electric powers to the LED load such that the light-emitting unit respectively generates at least a low level illumination and at least a high level illumination to perform different illumination modes according to signals received from the light sensing control unit and the motion sensing unit; wherein the power supply unit includes an AC/DC power converter to convert AC power into DC powers required for operating the LED security light, wherein the power source is a DC power source configured in the power supply unit, wherein the semiconductor switching device is an unidirectional semiconductor switching device, wherein the control signal is a pulse width modulation signal to control the switching circuitry for delivering different average electric currents from the power source to drive the light-emitting unit for generating different illuminations; wherein a configuration of the LED load and the power source is designed to be an adequate combination of in parallel and in series connections such that the average electric current passing through each LED of the LED load remains at an adequate level and a voltage V across each LED of the LED load complies with an operating constraint of V_(th)<V<V_(max) featuring electrical characteristics of the LED, wherein V_(th) is a minimum threshold voltage required to trigger the LED to start emitting light and V_(max) is a maximum operating voltage across the LED to avoid a thermal damage or burning out of LED construction; wherein a time setting unit is further installed for adjusting and setting a time duration for each of the different illumination modes, wherein when an ambient light detected by the light sensing control unit is lower than a first predetermined value, the loading and power control unit operates to turn on the LED load to perform a first illumination mode for a first predetermined time duration preset by the time setting unit, wherein when a motion intrusion is detected by the motion sensing unit, the loading and power control unit manages to increase the average electrical power transmitted to the LED load to perform a second illumination mode for a second predetermined time duration preset by the time setting unit, wherein the light intensity of said second illumination mode is higher than the light intensity of said first illumination mode, wherein when the ambient light detected by the light sensing control unit is higher than a second predetermined value, the loading and power control unit operates to turn off the LED load.
 7. An LED security light control device, comprising: a loading and power control unit; a light sensing control unit; a motion sensing unit; and a power supply unit; wherein the LED security light control device is electrically connected to an LED load configured with a plurality of LEDs, wherein the loading and power control unit comprises a controller and a switching circuitry, wherein the controller is electrically coupled with the switching circuitry, wherein the switching circuitry is electrically connected between a power source and the LED load, wherein the switching circuitry comprises at least a semiconductor switching device for controlling transmission of different average electric powers delivered to the LED load, wherein the controller outputs a control signal to control the switching circuitry for delivering different average electric powers from the power source to drive the LED load for performing at least two different illumination modes with different light intensities according to signals received from the light sensing control unit and the motion sensing unit; wherein the power supply unit includes an AC/DC power converter to convert AC power source into DC powers required for operating the LED security light control device, wherein the power source is a DC power source configured in the power supply unit, wherein the semiconductor switching device is an unidirectional semiconductor switching device, wherein the controller outputs the control signal to control the switching circuitry to deliver different average electric currents from the power source to drive the LED load for generating different illuminations; wherein a configuration of the LED load and the power source is designed to be an adequate combination of in parallel and in series connections such that the average electric current passing through each LED of the LED load remains at an adequate level and a voltage V across each LED complies with an operating constraint of V_(th)V<V_(max) featuring electrical characteristics of the LED, wherein V_(th) is a minimum threshold voltage required to trigger the LED to start emitting light and V_(max) is a maximum operating voltage across the LED to avoid a thermal damage or burning out of LED construction.
 8. The LED security light control device according to claim 7, wherein the value of V_(th) is equal to or greater than 2.5 volts, wherein the value of V_(max) is in a range between 3.5 volts and 20 volts depending on a packaging specification of the LED.
 9. The LED security light control device according to claim 8, wherein the value of the voltage V across each LED is confined to be in an operating range from 2.5 volts to 20 volts.
 10. The LED security light control device according to claim 7, wherein the LED security light control device is detachably connected to an LED load via a screw-in or plug-in configuration, wherein the LED security light control device is configured with a socket base, and the LED load is constructed with a screw-in head or a plug-in head for making an electrical connection with each other.
 11. The LED security light control device according to claim 10, wherein the LED load, when being connected with the LED security light control device, is angle adjustable.
 12. The LED security light control device according to claim 10, wherein the LED load, when being connected with the LED security light control device, is non-angle adjustable.
 13. The LED security light control device according to claim 7, wherein the controller is an integrated circuit device programmable for generating the control signal.
 14. The LED security light control device according claim 7, wherein the controller is an application specific integrated circuit customized for generating the control signal.
 15. An LED security light control device, comprising: a loading and power control unit; a light sensing control unit; a motion sensing unit; and a power supply unit; wherein the LED security light control device is electrically connected to an LED load configured with a plurality of LEDs, wherein the loading and power control unit comprises a controller and a switching circuitry, wherein the controller is electrically coupled with the switching circuitry, wherein the switching circuitry is electrically connected between a power source and the LED load, wherein the switching circuitry comprises at least a semiconductor switching device for controlling transmission of different average electric powers delivered to the LED load, wherein the controller outputs a control signal to control the switching circuitry for delivering different average electric powers from the power source to drive the LED load for performing at least two different illumination modes with different light intensities according to signals received from the light sensing control unit and the motion sensing unit; wherein the power supply unit includes an AC/DC power converter to convert AC power source into DC powers required for operating the LED security light control device, wherein the power source is a DC power source configured in the power supply unit, wherein the semiconductor switching device is an unidirectional semiconductor switching device, wherein the controller outputs the control signal to control the switching circuitry to deliver different average electric currents from the power source to drive the LED load for generating different illuminations; wherein a configuration of the LED load and the power source is designed to be an adequate combination of in parallel and in series connections such that the average electric current passing through each LED of the LED load remains at an adequate level and a voltage V across each LED complies with an operating constraint of V_(th)V<V_(max) featuring electrical characteristics of the LED, wherein V_(th) is a minimum threshold voltage required to trigger the LED to start emitting light and V_(max) is a maximum operating voltage across the LED to avoid a thermal damage or burning out of LED construction; wherein a time setting unit is further installed for adjusting and setting a time duration for each of various illumination modes, wherein when an ambient light detected by the light sensing control unit is lower than a first predetermined value, the loading and power control unit operates to turn on the LED load to perform a first illumination mode for a first predetermined time duration preset by the time setting unit, wherein when a motion intrusion is detected by the motion sensing unit, the loading and power control unit manages to increase the average electrical power transmitted to the LED load to perform a second illumination mode for a second predetermined time duration preset by the time setting unit, wherein the light intensity of said second illumination mode is higher than the light intensity of said first illumination mode, wherein when the ambient light detected by the light sensing control unit is higher than a second predetermined value, the loading and power control unit operates to turn off the LED load.
 16. An LED security light, comprising: a light-emitting unit, including an LED load configured with a plurality of LEDs; a loading and power control unit; a light sensing control unit; a motion sensing unit; and a power supply unit; wherein the light-emitting unit is non-angle adjustable to provide illumination projection for security protection, wherein the loading and power control unit comprises a controller and a switching circuitry, wherein the controller is electrically coupled with the switching circuitry, wherein the switching circuitry is electrically connected between a power source and the LED load of the light-emitting unit, wherein the switching circuitry comprises at least a semiconductor switching device for controlling transmission of different electric powers delivered to the LED load, wherein the controller outputs a control signal to control the switching circuitry for delivering different average electric powers from the power source to drive the light-emitting unit for generating different illuminations, wherein the controller controls the switching circuitry to deliver different average electric powers to the LED load such that the light-emitting unit respectively generates at least a low level illumination and at least a high level illumination according to signals received from the light sensing control unit and the motion sensing unit; wherein the power supply unit includes an AC/DC power converter to convert AC power into DC powers required for operating the LED security light, wherein the power source is a DC power source configured in the power supply unit, wherein the semiconductor switching device is an unidirectional semiconductor switching device, wherein the control signal is a pulse width modulation signal to control the switching circuitry for delivering different average electric currents from the power source to drive the light-emitting unit for generating different illuminations; wherein a configuration of the LED load and the power source is designed to be an adequate combination of in parallel and in series connections such that the average electric current passing through each LED of the LED load remains at an adequate level and a voltage V across each LED complies with an operating constraint of V_(th)V<V_(max) featuring electrical characteristics of the LED, wherein V_(th) is a minimum threshold voltage required to trigger the LED to start emitting light and V_(max) is a maximum operating voltage across the LED to avoid a thermal damage or burning out of LED construction.
 17. The LED security light according to claim 16, wherein the value of V_(th) is equal to or greater than 2.5 volts, wherein the value of V_(max) is in a range between 3.5 volts and 20 volts depending on a packaging specification of the LED.
 18. The LED security light according to claim 17, wherein the value of the voltage V across each LED is confined to be in an operating range from 2.5 volts to 20 volts.
 19. The LED security light according to claim 16, wherein the controller is an integrated circuit device programmable for generating the control signal.
 20. The LED security light according claim 16, wherein the controller is an application specific integrated circuit customized for generating the control signal.
 21. An LED security light, comprising: a light-emitting unit, including an LED load configured with a plurality of LEDs; a loading and power control unit; a light sensing control unit; a motion sensing unit; and a power supply unit; wherein the light-emitting unit is non-angle adjustable to provide illumination projection for security protection, wherein the loading and power control unit comprises a controller and a switching circuitry, wherein the controller is electrically coupled with the switching circuitry, wherein the switching circuitry is electrically connected between a power source and the LED load of the light-emitting unit, wherein the switching circuitry comprises at least a semiconductor switching device for controlling transmission of different electric powers delivered to the LED load, wherein the controller outputs a control signal to control the switching circuitry for delivering different average electric powers from the power source to drive the light-emitting unit for generating different illuminations, wherein the controller controls the switching circuitry to deliver different average electric powers to the LED load such that the light-emitting unit respectively generates at least a low level illumination and at least a high level illumination according to signals received from the light sensing control unit and the motion sensing unit; wherein the power supply unit includes an AC/DC power converter to convert AC power into DC powers required for operating the LED security light, wherein the power source is a DC power source configured in the power supply unit, wherein the semiconductor switching device is an unidirectional semiconductor switching device, wherein the control signal is a pulse width modulation signal to control the switching circuitry for delivering different average electric currents from the power source to drive the light-emitting unit for generating different illuminations; wherein a configuration of the LED load and the power source is designed to be an adequate combination of in parallel and in series connections such that the average electric current passing through each LED of the LED load remains at an adequate level and a voltage V across each LED complies with an operating constraint of V_(th)<V<V_(max) featuring electrical characteristics of the LED, wherein V_(th) is a minimum threshold voltage required to trigger the LED to start emitting light and V_(max) is a maximum operating voltage across the LED to avoid a thermal damage or burning out of LED construction; wherein a time setting unit is further installed for adjusting and setting a time duration for each of the different illumination modes, wherein when an ambient light detected by the light sensing control unit is lower than a first predetermined value, the loading and power control unit operates to turn on the LED load to perform a first illumination mode for a first predetermined time duration preset by the time setting unit, wherein when a motion intrusion is detected by the motion sensing unit, the loading and power control unit manages to increase the average electrical power transmitted to the LED load to perform a second illumination mode for a second predetermined time duration preset by the time setting unit, wherein the light intensity of said second illumination mode is higher than the light intensity of said first illumination mode, wherein when the ambient light detected by the light sensing control unit is higher than a second predetermined value, the loading and power control unit operates to turn off the LED load.
 22. An LED security light, comprising: a light-emitting unit, including an LED load configured with a plurality of LEDs; a loading and power control unit; a light sensing control unit; a motion sensing unit; and a power supply unit; wherein the loading and power control unit comprises a controller and a switching circuitry, wherein the controller is electrically coupled with the switching circuitry, wherein the switching circuitry is electrically connected between a power source and the LED load of the light-emitting unit, wherein the switching circuitry comprises at least a semiconductor switching device for controlling transmission of different average electric powers delivered to the LED load, wherein the controller outputs a control signal to control the switching circuitry for delivering different average electric powers from the power source to drive the light-emitting unit for generating different illuminations, wherein the controller controls the switching circuitry to deliver different average electric powers to the LED load such that the light-emitting unit respectively generates at least a low level illumination and at least a high level illumination according to signals received from the light sensing control unit and the motion sensing unit; wherein the power supply unit is a battery module to output DC power for operating the LED security light, wherein the power source is a DC power source configured in the battery module, wherein the semiconductor switching device is an unidirectional semiconductor switching device, wherein the controller outputs the control signal to control the switching circuitry for delivering different average electric currents from the power source to drive the light-emitting unit for generating different illuminations; wherein a configuration of the LED load and the power source is designed to be an adequate combination of in parallel and in series connections such that the average electric current passing through each LED of the LED load remains at an adequate level and a voltage V across each LED complies with an operating constraint of V_(th)<V<V_(max) featuring electrical characteristics of the LED, wherein V_(th) is a minimum threshold voltage required to trigger the LED to start emitting light and V_(max) is a maximum operating voltage across the LED to avoid a thermal damage or burning out of LED construction.
 23. The LED security light according to claim 22, wherein the value of V_(th) is equal to or greater than 2.5 volts, wherein the value of V_(max) is in a range between 3.5 volts and 20 volts depending on a packaging specification of the LED.
 24. The LED security light according to claim 23, wherein the value of the voltage V across each LED is confined to be in an operating range from 2.5 volts to 20 volts.
 25. The LED security light according to claim 22, wherein the controller is an integrated circuit device programmable for generating the control signal.
 26. The LED security light according claim 22, wherein the controller is an application specific integrated circuit customized for generating the control signal.
 27. The LED security light according to claim 22, wherein the battery module is a solar battery module including a solar panel, a charging circuitry and a rechargeable battery.
 28. An LED security light, comprising: a light-emitting unit, including an LED load configured with a plurality of LEDs; a loading and power control unit; a light sensing control unit; a motion sensing unit; and a power supply unit; wherein the loading and power control unit comprises a controller and a switching circuitry, wherein the controller is electrically coupled with the switching circuitry, wherein the switching circuitry is electrically connected between a power source and the LED load of the light-emitting unit, wherein the switching circuitry comprises at least a semiconductor switching device for controlling transmission of different average electric powers delivered to the LED load, wherein the controller outputs a control signal to control the switching circuitry for delivering different average electric powers from the power source to drive the light-emitting unit for generating different illuminations, wherein the controller controls the switching circuitry to deliver different average electric powers to the LED load such that the light-emitting unit respectively generates at least a low level illumination and at least a high level illumination according to signals received from the light sensing control unit and the motion sensing unit; wherein the power supply unit is a battery module to output DC power for operating the LED security light, wherein the power source is a DC power source configured in the battery module, wherein the semiconductor switching device is an unidirectional semiconductor switching device, wherein the controller outputs the control signal to control the switching circuitry for delivering different average electric currents from the power source to drive the light-emitting unit for generating different illuminations; wherein a configuration of the LED load and the power source is designed to be an adequate combination of in parallel and in series connections such that the average electric current passing through each LED of the LED load remains at an adequate level and a voltage V across each LED complies with an operating constraint of V_(th)<V<V_(max) featuring electrical characteristics of the LED, wherein V_(th) is a minimum threshold voltage required to trigger the LED to start emitting light and V_(max) is a maximum operating voltage across the LED to avoid a thermal damage or burning out of LED construction; wherein a time setting unit is further installed for adjusting and setting a time duration for each of the different illumination modes, wherein when an ambient light detected by the light sensing control unit is lower than a first predetermined value, the loading and power control unit operates to turn on the LED load to perform a first illumination mode for a first predetermined time duration preset by the time setting unit, wherein when a motion intrusion is detected by the motion sensing unit, the loading and power control unit manages to increase the average electrical power transmitted to the LED load to perform a second illumination mode for a second predetermined time duration preset by the time setting unit, wherein the light intensity of said second illumination mode is higher than the light intensity of said first illumination mode, wherein when the ambient light detected by the light sensing control unit is higher than a second predetermined value, the loading and power control unit operates to turn off the LED load.
 29. An LED security light, comprising: a light-emitting unit, including an LED load; a loading and power control unit; a light sensing control unit; a motion sensing unit; and a power supply unit; wherein the loading and power control unit comprises a controller and a switching circuitry, wherein the controller is electrically coupled with the switching circuitry, wherein the switching circuitry is electrically connected between a power source and the LED load of the light-emitting unit, wherein the switching circuitry comprises at least a semiconductor switching device for controlling transmission of different average electric powers delivered to the LED load, wherein the controller outputs a control signal to control the switching circuitry for delivering different average electric powers from the power source to drive the light-emitting unit for generating different illuminations, wherein the controller controls the switching circuitry to deliver different average electric powers to LED load such that the light-emitting unit respectively generates at least a low level illumination and at least a high level illumination according to signals received from the light sensing control unit and the motion sensing unit; wherein the power supply unit includes an AC/DC power converter to convert AC power of an AC power source into DC power for operating the LED security light, wherein the power source is the AC power source, wherein the LED load of the light-emitting unit is adaptable to the AC power source, wherein the switching circuitry includes a phase controller containing a bidirectional semiconductor switching device, wherein the bidirectional semiconductor switching device is connected in series between the AC power source and the LED load, and wherein the controller incorporating with a zero-crossing detection circuit outputs a time delay pulse lagging behind the zero-crossing point in each half cycle of the AC power source to control the conduction rate of the phase controller for delivering different average AC powers to drive the LED load for performing different illumination modes according to signals received from the light sensing control unit and the motion sensing unit.
 30. The LED security light according to claim 29, wherein the controller is an integrated circuit device programmable for generating the control signal.
 31. The LED security light according claim 29, wherein the controller is an application specific integrated circuit customized for generating the control signal.
 32. The LED security light according to claim 29, wherein the LED load is a DC LED module comprising a plurality of LEDs configured in parallel and/or in series connections, wherein the DC LED module is electrically connected to a full wave rectifier, wherein the full wave rectifier converts the AC power delivered by the phase controller into a DC power to drive the LED load for generating illumination.
 33. The LED security light according to claim 32, wherein a configuration of the DC LED module and the power source is designed to be an adequate combination of in parallel and in series connections such that an average electric current passing through each LED of the DC LED module remains at an adequate level and a voltage V across each LED complies with an operating constraint of V_(th)<V<V_(max) featuring electrical characteristics of the LED, wherein V_(th) is a minimum threshold voltage required to trigger the LED to start emitting light and V_(max) is a maximum operating voltage across the LED to avoid a thermal damage or burning out of LED construction.
 34. The LED security light according to claim 33, wherein the value of V_(th) is equal to or greater than 2.5 volts, wherein the value of V_(max) is in a range between 3.5 volts and 20 volts depending on a packaging specification of the LED.
 35. The LED security light according to claim 34, wherein the value of the voltage V across each LED is confined to be in an operating range from 2.5 volts to 20 volts.
 36. The LED security light according to claim 29, wherein the LED load is a LED module including two polarity reverse LED arrays connected in parallel, wherein the first LED array conducts in a positive half cycle of the AC power controlled by the loading and power control unit while the second LED array conducts in a negative half cycle of the AC power controlled by the loading and power control unit.
 37. The LED security light according to claim 36, wherein a configuration of the two polarity reverse LED arrays is designed to be an adequate combination of in parallel and in series connections such that an electric current passing through each LED of the LED load remains at an adequate level and a voltage V across each LED complies with an operating constraint of V_(th)<V<V_(max) featuring electrical characteristics of the LED, wherein V_(th) is a minimum threshold voltage required to trigger the LED to start emitting light and V_(max) is a maximum operating voltage across the LED to avoid a thermal damage or burning out of LED construction.
 38. The LED security light according to claim 37, wherein the value of V_(th) is equal to or greater than 2.5 volts, wherein the value of V_(max) is in a range between 3.5 volts and 20 volts depending on a packaging specification of the LED.
 39. The LED security according to claim 38, wherein the value of the voltage V across each LED is confined to be in an operating range from 2.5 volts to 20 volts.
 40. The LED security light according to claim 29, wherein in order to ensure a successful conduction the phase controller is confined to operate in a time phase domain between t₀ and ½f−t₀, wherein f is the frequency of the AC power source, and t₀ is a corresponding time phase of a cut-in voltage at which the LED load starts to emit light in each positive and negative half cycle of the AC power.
 41. An LED security light, comprising: a light-emitting unit, including an LED load; a loading and power control unit; a light sensing control unit; a motion sensing unit; and a power supply unit; wherein the loading and power control unit comprises a controller and a switching circuitry, wherein the controller is electrically coupled with the switching circuitry, wherein the switching circuitry is electrically connected between a power source and the LED load of the light-emitting unit, wherein the switching circuitry comprises at least a semiconductor switching device for controlling transmission of different average electric powers delivered to the LED load, wherein the controller outputs a control signal to control the switching circuitry for delivering different average electric powers from the power source to drive the light-emitting unit for generating different illuminations, wherein the controller controls the switching circuitry to deliver different average electric powers to LED load such that the light-emitting unit respectively generates at least a low level illumination and at least a high level illumination according to signals received from the light sensing control unit and the motion sensing unit; wherein the power supply unit includes an AC/DC power converter to convert AC power of an AC power source into DC power for operating the LED security light, wherein the power source is the AC power source, wherein the LED load of the light-emitting unit is adaptable to the AC power source, wherein the switching circuitry includes a phase controller containing a bidirectional semiconductor switching device, wherein the bidirectional semiconductor switching device is connected in series between the AC power source and the LED load, and wherein the controller incorporating with a zero-crossing detection circuit outputs a time delay pulse lagging behind the zero-crossing point in each half cycle of the AC power source to control the conduction rate of the phase controller for delivering different average AC powers to drive the LED load for performing different illumination modes according to signals received from the light sensing control unit and the motion sensing unit; wherein a time setting unit is further installed for adjusting and setting a time duration for each of various illumination modes, wherein when an ambient light detected by the light sensing control unit is lower than a first predetermined value, the loading and power control unit operates to turn on the LED load to perform a first illumination mode for a first predetermined time duration preset by the time setting unit, wherein when a motion intrusion is detected by the motion sensing unit, the loading and power control unit operates to increase the average electrical power transmitted to the LED load to perform a second illumination mode for a second predetermined time duration preset by the time setting unit, wherein the light intensity of said second illumination mode is higher than the light intensity of said first illumination mode, wherein when the ambient light detected by the light sensing control unit is higher than a second predetermined value, the loading and power control unit manages to turn off the LED load.
 42. An LED security light control device, comprising: a loading and power control unit; a light sensing control unit; a motion sensing unit; and a power supply unit; wherein the LED security light control device is electrically connected to an LED load configured with a plurality of LEDs; wherein the loading and power control unit comprises a controller and a switching circuitry, wherein the switching circuitry being coupled with the controller is electrically connected between a power source and the LED load, wherein the controller outputs a control signal to control the switching circuitry for delivering different average electric powers from the power source to drive the LED load for generating different illuminations such that the LED load respectively performs at least two illumination modes with different light intensities according to signals received from the light sensing control unit and the motion sensing unit; wherein the power supply unit is a battery module to output DC power for operating the LED security light control device, wherein the power source is a DC power source in the battery module, wherein the semiconductor switching device is an unidirectional semiconductor switching device, wherein the controller outputs the control signal to control the switching circuitry for delivering different average electric currents from the power source to drive the LED load for generating different illuminations; wherein a configuration of the LED load and the power source is designed to be an adequate combination of in parallel and in series connections such that the average electric current passing through each LED of the LED load remains at an adequate level and a voltage V across each LED complies with an operating constraint of V_(th)<V<V_(max) featuring electrical characteristics of the LED, wherein V_(th) is a minimum threshold voltage required to trigger the LED to start emitting light and V_(max) is a maximum operating voltage across the LED to avoid a thermal damage or burning out a semiconductor structure of LED construction.
 43. The LED security light control device according to claim 42, wherein the value of V_(th) is equal to or greater than 2.5 volts, wherein the value of V_(max) is in a range between 3.5 volts and 20 volts depending on a packaging specification of the LED.
 44. The LED security light control device according to claim 43, wherein the value of the voltage V across each LED is confined to be in an operating range from 2.5 volts to 20 volts.
 45. The LED security light control device according to claim 42, wherein the LED security light control device is detachably connected to a LED load via a screw-in or plug-in configuration, wherein the LED security light control device is configured with a socket base, and the LED load is constructed with a screw-in head or a plug-in head for making an electrical connection with each other.
 46. The LED security light control device according to claim 45, wherein the LED load, when being connected with the LED security light control device, is angle adjustable.
 47. The LED security light control device according to claim 45, wherein the LED load, when being connected with the LED security light control device, is non-angle adjustable.
 48. The LED security light control device according to claim 42, wherein the controller is an integrated circuit device programmable for generating the control signal.
 49. The LED security light control device according claim 42, wherein the controller is an application specific integrated circuit customized for generating the control signal.
 50. The LED security light control device according to claim 42, wherein the battery module is a solar battery module including a solar panel, a charging circuitry and a rechargeable battery.
 51. An LED security light control device, comprising: a loading and power control unit; a light sensing control unit; a motion sensing unit; and a power supply unit; wherein the LED security light control device is electrically connected to an LED load configured with a plurality of LEDs; wherein the loading and power control unit comprises a controller and a switching circuitry, wherein the switching circuitry being coupled with the controller is electrically connected between a power source and the LED load, wherein the controller outputs a control signal to control the switching circuitry for delivering different average electric powers from the power source to drive the LED load for generating different illuminations such that the LED load respectively performs at least two illumination modes with different light intensities according to signals received from the light sensing control unit and the motion sensing unit; wherein the power supply unit is a battery module to output DC power for operating the LED security light control device, wherein the power source is a DC power source in the battery module, wherein the semiconductor switching device is an unidirectional semiconductor switching device, wherein the controller outputs the control signal to control the switching circuitry for delivering different average electric currents from the power source to drive the LED load for generating different illuminations; wherein a configuration of the LED load and the power source is designed to be an adequate combination of in parallel and in series connections such that the average electric current passing through each LED of the LED load remains at an adequate level and a voltage V across each LED complies with an operating constraint of V_(th)<V<V_(max) featuring electrical characteristics of the LED, wherein V_(th) is a minimum threshold voltage required to trigger the LED to start emitting light and V_(max) is a maximum operating voltage across the LED to avoid a thermal damage or burning out a semiconductor structure of LED construction; wherein a time setting unit is further installed for adjusting and setting a time duration for each of the different illumination modes, wherein when an ambient light detected by the light sensing control unit is lower than a first predetermined value, the loading and power control unit operates to perform a first illumination mode for a first predetermined time duration preset by the time setting unit, wherein when a motion intrusion is detected by the motion sensing unit, the loading and power control unit operates to increase the average electric power transmitted to the LED load to perform a second illumination mode for a second predetermined time duration preset by the time setting unit, wherein the light intensity of said second illumination mode is higher than the light intensity of said first illumination mode, wherein when the ambient light detected by the light sensing control unit is higher than a second predetermined value, the loading and power control unit operates to turn off the LED load.
 52. An LED security light control device, comprising: a loading and power control unit; a light sensing control unit; a motion sensing unit; and a power supply unit; wherein the LED security light control device is electrically connectable to an LED load, wherein the loading and power control unit comprises a controller and a switching circuitry, wherein the switching circuitry being coupled with the controller is electrically connected between a power source and the LED load, wherein the controller outputs a control signal to control the switching circuitry for delivering different average electric powers from the power source to drive the LED load for generating different illuminations, wherein the controller controls the switching circuitry to deliver different average electric powers to the LED load such that the LED load respectively performs at least two illumination modes with different light intensities according to signals received from the light sensing control unit and the motion sensing unit; wherein the power supply unit includes an AC/DC power converter to convert AC power of an AC power source into DC power for operating the LED security light, wherein the power source is the AC power source, wherein the LED load is adaptable to the AC power source, wherein the switching circuitry includes a phase controller containing a bidirectional semiconductor switching device, wherein the bidirectional semiconductor switching device is connectable in series between the AC power source and the LED load, and wherein the controller incorporating with a zero-crossing detection circuit outputs a time delay pulse lagging behind the zero-crossing point in each half cycle of the AC power source to control the conduction rate of the phase controller for delivering different average AC power to drive the LED load for performing different illumination modes according to signals received from the light sensing control unit and the motion sensing unit.
 53. The LED security light control device according to claim 52, wherein the LED security light control device is detachably connected to the LED load via a screw-in or plug-in configuration, wherein the LED security light control device is configured with a socket base, and the LED load is constructed with a screw-in head or a plug-in head for making an electrical connection with each other.
 54. The LED security light control device according to claim 53, wherein the LED load, when being connected with the LED security light control device, is angle adjustable.
 55. The LED security light control device according to claim 53, wherein the LED load, when being connected with the LED security light control device, is non-angle adjustable.
 56. The LED security light control device according to claim 52, wherein the controller is an integrated circuit device programmable for generating the control signal.
 57. The LED security light control device according claim 52, wherein the controller is an application specific integrated circuit customized for generating the control signal.
 58. The LED security light control device according to claim 52, wherein the LED load is a DC LED module comprising a plurality of LEDs configured with adequate combination of in parallel and in series connections, wherein the DC LED module is electrically connected to a full wave rectifier, wherein the full wave rectifier converts the AC power delivered by the phase controller into a DC power to drive the LED load for generating illumination.
 59. The LED security light control device according to claim 58, wherein a configuration of the DC LED module and the power source is designed to be an adequate combination of in parallel and in series connections such that an average electric current passing through each LED of the LED load remains at an adequate level and a voltage V across each LED complies with an operating constraint of V_(th)<V<V_(max) featuring electrical characteristics of the LED, wherein V_(th) is a minimum threshold voltage required to trigger the LED to start emitting light and V_(max) is a maximum operating voltage across the LED to avoid a thermal damage or burning out of LED construction.
 60. The LED security light control device according to claim 59, wherein the value of V_(th) is equal to or greater than 2.5 volts, wherein the value of V_(max) is in a range between 3.5 volts and 20 volts depending on a packaging specification of the LED.
 61. The LED security light control device according to claim 60, wherein the value of the voltage V across each LED is confined to be in an operating range from 2.5 volts to 20 volts.
 62. The LED security light control device according to claim 52, wherein the LED load is a LED module including two polarity reverse LED arrays connected in parallel, wherein the first LED array conducts in a positive half cycle of the AC power controlled by the loading and power control unit while the second LED array conducts in a negative half cycle of the AC power controlled by the loading and power control unit.
 63. The LED security light control device according to claim 62, wherein a configuration of the two polarity reverse LED arrays is designed to be an adequate combination of in parallel and in series connections such that an average electric current passing through each LED of the LED load remains at an adequate level and a voltage V across each LED complies with an operating constraint of V_(th)<V<V_(max) featuring electrical characteristics of the LED, wherein V_(th) is a minimum threshold voltage required to trigger the LED to start emitting light and V_(max) is a maximum operating voltage across the LED to avoid a thermal damage or burning out of LED construction.
 64. The LED security light control device according to claim 63, wherein the value of V_(th) is equal to or greater than 2.5 volts, wherein the value of V_(max) is in a range between 3.5 volts and 20 volts depending on a packaging specification of the LED.
 65. The LED security light control device according to claim 63, wherein the value of the voltage V across each LED is confined to be in an operating range from 2.5 volts to 20 volts.
 66. The LED security light control device according to claim 52, wherein in order to ensure a successful conduction the phase controller is confined to operate in a time phase domain between t₀ and ½f−t₀, wherein f is the frequency of the AC power source, and t0 is a corresponding time phase of a cut-in voltage at which the connected LED load starts to emit light in each positive and negative half cycle.
 67. An LED security light control device, comprising: a loading and power control unit; a light sensing control unit; a motion sensing unit; and a power supply unit; wherein the LED security light control device is electrically connectable to an LED load, wherein the loading and power control unit comprises a controller and a switching circuitry, wherein the switching circuitry being coupled with the controller is electrically connected between a power source and the LED load, wherein the controller outputs a control signal to control the switching circuitry for delivering different average electric powers from the power source to drive the LED load for generating different illuminations, wherein the controller controls the switching circuitry to deliver different average electric powers to the LED load such that the LED load respectively performs at least two illumination modes with different light intensities according to signals received from the light sensing control unit and the motion sensing unit; wherein the power supply unit includes an AC/DC power converter to convert AC power of an AC power source into DC power for operating the LED security light, wherein the power source is the AC power source, wherein the LED load is adaptable to the AC power source, wherein the switching circuitry includes a phase controller containing a bidirectional semiconductor switching device, wherein the bidirectional semiconductor switching device is connectable in series between the AC power source and the LED load, and wherein the controller incorporating with a zero-crossing detection circuit outputs a time delay pulse lagging behind the zero-crossing point in each half cycle of the AC power source to control the conduction rate of the phase controller for delivering different average AC power to drive the LED load for performing different illumination modes according to signals received from the light sensing control unit and the motion sensing unit; wherein a time setting unit is further installed for adjusting and setting a time duration for each of various illumination modes; wherein when an ambient light detected by the light sensing control unit is lower than a first predetermined value, the loading and power control unit operates to turn on the LED load to perform a first illumination mode for a first predetermined time duration preset by the time setting unit and at the same time to activate the motion sensing unit, wherein when a motion intrusion is detected by the motion sensing unit, the loading and power control unit operates to increase the average electric power transmitted to the LED load to perform a second illumination mode for a second predetermined time duration preset by the time setting unit, wherein the light intensity of said second illumination mode is higher than the light intensity of said first illumination mode, wherein when the ambient light detected by the light sensing control unit is higher than a second predetermined value, the loading and power control unit operates to turn off the LED load. 